Far UV Extinction and the 2175 Angstrom Bump
Abstract
Work in progress suggests that the far Uv curvature observed in uv extinction curves may be related to the width of the 2175A bump. If verified, such a relationship would be strong evidence for a graphitic origin of the bump. This is because graphite particles are expected to have a second resonance in their optical properties near 80oA whose width broadens in step with the one at 2175A. Consequently, a relationship between the bump width and the FUV curvature would be expected because the FUV curvature would actually be the red wing of the widening 800A resonance protruding further into the accessable UV. more observations are needed of extinction curves with broad and narrow bumps in order to verify the observed trend. We describe how to identify such stars using available ANS photometry.
- Publication:
-
IUE Proposal
- Pub Date:
- 1987
- Bibcode:
- 1987iue..prop.2809M